Update quick-start.md to use the current stable release

Hi!

This is a proposed update to take into account the current stable release. I removed the references to branches as they don't seem to exist anymore. The sentence about the procedure to get the latest developments is maybe superfluous.

mentioned in commit 8312bad7

mentioned in commit platform@4c6fab10

Uff, I wasn't very much awake while doing the merge. Thanks for noticing this, I merged it in: 8312bad7

closed